1. Field
Embodiments relate to a charge control system of a battery pack.
2. Description of the Related Art
Secondary batteries are actively being researched due to development of portable electronic devices such as cellular phones, notebook computers, camcorders and Personal Digital Assistants (PDAs).
Such secondary batteries are manufactured in a battery pack type that includes a battery and a charge/discharge circuit. A battery is charged by an external power source or is discharged by an external load, through an external terminal disposed in a battery pack. That is, when the battery pack is connected to the external power source through the external terminal, the battery is charged by the external power source that is supplied through the external terminal and the charge/discharge circuit. Moreover, when the external load is connected to the battery pack through the external terminal, a discharge operation is performed where the power source of the battery is supplied to the external load through the charge/discharge circuit and the external terminal. At this point, the charge/discharge circuit controls charge/discharge of the battery between the external terminal and the battery.
Generally, batteries are charged with the maximum charge current until the voltages of the batteries reach a certain voltage level and then a charge current is slowly reduced when the voltages of the batteries reach a certain voltage level.
In the cases of notebook computers, when a charge/discharge switch is disabled in a charge/discharge circuit, a fuse is cut and thus charge of a battery is controlled. However, in the cases of electric bicycles, it is difficult to apply a fuse because a working voltage is high and a high current flows.